Z-World eDisplay OP7200, Руководство пользователя

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User’s Manual 125
B.2 Batteries and External Battery Connections
The SRAM and the real-time clock have battery backup. Power to the SRAM and the real-
time clock (VRAM) on the OP7200’s RabbitCore module is provided by two different
sources, depending on whether the main part of the OP7200 is powered or not. When the
OP7200 is powered normally, and Vcc is within operating limits, the SRAM and the real-
time clock are powered from Vcc. If power to the board is lost or falls below 4.63 V, the
VRAM and real-time clock power will come from the battery. The reset generator circuit
controls the source of power by way of its
/RESET output signal.
A replaceable 265 mA·h lithium battery provides power to the real-time clock and SRAM
when external power is removed from the circuit board. The drain on the battery is typically
less than 10 µA when there is no external power applied to the OP7200, and so the expected
shelf life of the battery is
The drain on the battery is typically less than 4 µA when external power is applied, and so
the expected battery in-service life is
B.2.1 Replacing the Backup Battery
The battery is user-replaceable, and is fitted in a battery holder. To replace the battery, lift
up on the spring clip and slide out the old battery. Use only a Panasonic BR2330 or equiv-
alent replacement battery, and insert it into the battery holder with the + side facing up.
NOTE: The SRAM contents and the real-time clock settings will be lost if the battery is
replaced with no power applied to the OP7200. Exercise care if you replace the battery
while external power is applied to the OP7200.
CAUTION: There is an explosion danger if the battery is short-circuited, recharged,
or replaced incorrectly. Replace the battery only with the same type or an equivalent
type recommended by the battery manufacturer. Dispose of used batteries according
to the battery manufacturer’s instructions.
265 mA·h
10 µA
------------------------
3.0 years. =
265 mA·h
4 µA
------------------------
7.5 years. =